What advantages does modern Fortran have over modern C++?

I'm trying to decide between Fortran and C++ for an application in scientific computing. It's not clear to me if Fortran still has advantages over other languages when it comes to performance. For example, I believe since Fortran enforces strict aliasing, better optimizations could be made by the compiler when compared to C before C99. I'm unsure of how C++ fits in here.

Fortran has been heavily used in engineering circles for 50 years now. That gives you two advantages if you work in those circles. First off, these folks care a lot about optimization. That means Fortran compilers tend to have the best optimizers around. The language itself is a lot more optimizable than Cish languages too, thanks to its lack of aliasing.

The second advantage is that Fortran's library support for number crunching simply cannot be beat. The best code is nearly always going to be the well-debugged code you don't have to write.

If your application doesn't fall under scientific, engineering, or number crunching in general, then neither of the above will be a big deal for you, so you may be better off looking elsewhere.